Referring to FIG. 1, a known receptacle 2 of this general type is shown. The receptacle 2 includes a strip-like conductor 1 formed integrally therewith. The receptacle 2 also includes a resilient contact plate 3 for contact with a flat surface of a flat-type plug A, and finger-shaped projections 5 and 5' extending from the opposite sides of the contact plate 3 through extensions 4 which are bent. The flat surfaces of the finger-shaped projections 5 and 5' are disposed perpendicular to the flat surfaces of the contact plate 3, and rounded heads 6 of the projections 5 and 5' are adapted to press against the other flat surface of the plug A. The contact plate 3 extends integrally from one end of the conductor 1. The plug A is adapted to be inserted into the receptacle in such a manner that the flat surfaces of the plug A are disposed perpendicular to longitudinal edges 7 of the conductor 1.
Referring to FIG. 2, the receptacle 2 of FIG. 1 is shaped by bending a stamped blank m along bending lines 8a to 8c indicated by broken lines.
When the strip-like conductor 1 is to be used as a bus bar circuit for a circuit board mounted within an electric connection box, it is often required, because of the limitations on the arrangement of the circuit and the direction of insertion of the flat-type plug A, to provide, as shown in FIG. 3, a receptacle 2' to which the plug A is adapted to be connected in such a manner that the plug A is disposed in parallel relation to the longitudinal edges 7 of the conductor 1.
FIGS. 4(a) to 4(d) show the steps of shaping the receptacle 2' of FIG. 3. First, as shown in FIGS. 4(a) and (b), on finger-shaped projection 5' of a blank m' is bent, using upper and lower dies 9 and 9'. At this time, since the contact plate 3 and the other finger-shaped projection 5 are supported by the lower die 9', the finger-shaped projection 5' is positively bent. However, as a result of the bending of the finger-shaped projection 5', when the contact plate 3 is to be bent relative to the other finger-shaped projection 5, using upper and lower dies 10 and 10' (FIGS. 4(c) and 4(d)), that portion 10a' of the lower die 10' supporting the extension 4 is so small and inadequate that a positive bending cannot be achieved. Therefore, a precision at this region (and hence a proper gap between the resilient contact plate 3 and a rounded head 6 of the finger-shaped projection 5) is affected, thus degrading the performance of the resultant receptacle 2'.
In order that the flat-type plug A can be inserted into a receptacle 2', with the flat surfaces of the plug A disposed in parallel relation to the longitudinal edges 7 of the conductor 1, when the finger-shaped projection 5 or the finger-shaped projection 5' is bent relative to that portion of the blank m' disposed forwardly of the conductor 1 as shown in FIG. 4(a), a positive bending cannot be achieved, thus adversely affecting the precision and performance of the receptacle.